SU(2) instantons with boundary jumps and spin tunneling in magnetic molecules

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Kececioglu, Ersin; Garg, Anupam;

Coherent state path integrals are shown in general to contain instantons with jumps at the boundaries, i.e., with boundary points lying outside classical parameter or phase space. As an example, the magnetic molecule Fe_8 is studied using a realistic Hamiltonian, and in... View more
  • References (16)
    16 references, page 1 of 2

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    [5] It should be stressed that our remarks apply only to tunneling, i.e., to infinite time propagators. Paths with nonclassical endpoints are known to be important for finite time problems, e.g., Larmor precession in the semiclassical approximation. In these cases, however, these are the only paths that contribute. There is no problem of which we are aware in which both types of paths, with and without jumps, need to be included.

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    [9] In this paper we only consider external fields along ˆz. Also, note that one can add a term proportional to J · J to H, since that commutes with H. This can change the 2 superficial appearance of H and the coefficients of Jx , etc. The physics, of course, is unaffected.

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